Refrigerating apparatus



July 12, 1938. L. .B. M. BUCHANAN 2,123,493

' REFRIGERATING APPARATUS Filed Nov. 11, 1.936

WITNESSES:

6 ATTORN;

INVENTOR v 1.551.157 5.M.5UCHHNHN Patented July 1% 193$ umrao s'mr EsPATENT oFFics v f "amass nnrnronna'rmo APPARATUS Leslie E. M. BuchananSpringfield, Mass, as-

signor to Westinghouse Electric & Manufacturing Company, EastPittsburgh, Pa., a corporation of Pennsylvania I Application November11, 1936, Serial-No 1103M crating apparatus employing a hermeticallysealed compressor mechanism and has for an object to provide improvedapparatus of this kind. A further object of my invention is to provideimproved means for conducting refrigerant vaporized in high and lowtemperature evaporators to the inlets of a hermetically sealedcompressor.

A further object dfmy invention is to provide a refrigerating systemhaving aplurality of evaporators and a hermetically sealed compressorofthe so-called, ported cylindertype wherein im-' proved meansare employedfor conducting the vaporized refrigerant to the compressor.

These and other objects are effected by my invention as "will beapparent from the following description and claimstakn in connectionwith this application, in which:

.Fig. 1 is a diagrammatic view showing a the accompanying drawing,forminga part of 5- temperature refrigerating'system having 9.hermetically'sealedcompressor and arranged in ac- Reference will now behad to Figs. 1 and a of I the drawing, wherein relatively low and highterm perature evaporators It and II are shown connected to a refrigerantcondensing unit 12 having a hermetically sealed compressor l3 and acondenser shownvat. M. The compressor I3 is preferably driven by anelectric motor l5, both ;of which are enclosed by a. It.

' shaft 19 that is journaled in theirame l1- and which carries a crank2| for actuating the comprefssor. The compressor Iii-includes a cylinderA. frame I1 is carried by the casing I6 inany suitable manner anddefines the'support for the motor l5and compressor l3. Openings 20 arepreferably provided in the frame IT. for permitting circulation ofvapor'ous refrigerant through the motor l5 for cooling the same. 7 Themotor 15 includes a rotor element l8 carried by a 22 having a'piston 23therein, the latter being reciprocated by the crank 2| through themedium of a connecting rod 24. An oil thrower 25 maybe employed fordistributing lubricant; shown at 28; over the moving element s'of themotor. and com.- pressor. I I

The cylinder 22 includes a valve structure,

I d 5 Claims. (01. 02- My invention relates to two temperaturerefrlgshown generally at 21 and disposed between the cylinder 22 and ahead 22. The valve structure 21 may be of any suitable type forcontrolling the passage of' refrigerant between the head 28 and thecylinder 22. The head 22 has an inlet forvaporous refrigerant shown at29 and a conduit 3| for compressed refrigerant extends from the head 28through the casing iii to the condenser H. A second inlet or port 32 forrefrigerant vapor is formed in the wall of the cylinder 22 and aconduit-33 provides communication between the inlet or port 32 and thehigher temperature evaporator ll, said conduit 33-passing through thecasing l6 as shown. The inlet 29 of the compressor I3 is'incommunication with the interior of the casing it which receives vaporousrefrigerant from the low temperature evaporator" I0 througha conduitfit. I

Liquid refrigerant in the condenser M is sup-.

--'plied to the evaporators ill and ll through suitable expansiondevices shown at'35 and 36. The flow of refrigerant from the evaporatorsHland II to the conduits 34 and 33, respectively, is con trolled bysuitable valves 31 and 38. Accordingly, refrigeration of bothevaporators may be effected byopening the'valves 31 and 38 and operatingthe com-pressor l3 or the evaporator-s l0 and II may be'selectivelyoperated byopening the valve asso--- ciated with the evaporator to beoperated.

A conduit 39 is connected between the conduits 33 and 34- and includesavalve M, the purpose of which is referred to hereinafter.

V Operation 'I'l'iecompressor mechanism described in the foregoing is ofthe so-called. ported cylinder type.

During operation, low pressure refrigerant is drawn into the cylinder 22as the pist'pn 23 descends, through the inlet2il and valve structure 21.l'he relatively highpressure refrigerant vapor' enters the cylinder 22through the port 32 when the latter is uncovered by the piston 23 nearthe end of, its stroke. The low pressure vapor in the cylinder 22 iscompressed by the higher pressure vapor so that, during the compressionstroke,

the piston compresses a mixture, of the vaporshaving' a densitysubstantially equal to the density ofthe' higher pressure vapor;

l0 and H are operated and their respective suction line valves. 31 and38 are open. 7

When the valve 31 is open and the 'valve 38 is closed, the lowertemperature evaporator only is operated. Accordingly vapor'ousrefrigerant is admitted to the cylinder 22 through the inlet Thisoperation. is effected during periods. when both evaporators pressor-mechanism. Thepresent application is' at this time is of no importanceand the only result thereof is a reduction in pressure in the conduit 33as far as the valve 38, to substantially the pressure value in thecylinder 22 at the time the port opens.

During periods when the higher temperature evaporator is operated, thevalves 21 and 38 are closed and open, respectively. At this time, the

valve ll is opened to permit the higher pressure vapor from theevaporator II to enter the casing through the conduits l9 and ,34, and,therefore, to effect admission of the vapor to the cylin; der'22 throughthe inlet 29. This operation preventsthe compressor from pulling a highvacuumin' the cylinder 22 prior to the time that the port 32 isuncovered, which condition would prevail if the higher pressure vaporwere admitted to evaporators circulates through the casing ii at alltimes that the compressor operates and,

therefore, cooling of the motor and compressor and the lubricant isefiected at' all times by the vapor. I

In my copending application, Serial No. 110,203,

filed November 11, 1936 and assigned to the Westinghouse'Electric 8:Manufacturing Com--, pany, I have disclosed and broadly claimed thesystem of controlling the flow of vapor from a plurality of evaporatorsto a multiple inlet comdirected to the application of such system to ahermetically sealed mechanism so that the cold gas from one or theother. of the evaporators is employed for cooling the mechanism in" thecasing at all times that the mechanism is operated.

In Fig. 2, Theme shown a two temperature system wherein the evaporatorsare operated to- Bether at all times that thesystem is active.

. The low and high temperature evaporators are shown at ill and II,respectively, and may be suppliedwith condensed refrigerant fromythecondenser it in the same manner as shown in Fig. 1. Elements which arecommon to both embodiments are represented by similar numerals in bothFigs. 1 and 2: The evaporators Ill and II may be connected to theinterior of the casing and the inlet port 32 in' this embodiment in thesame manner as shown in Fig. 1, but I prefer to show in Fig. 2 asecondmethod of connecting the evaporators to the hermetically sealedmechanism.

- The low temperature evaporator i is providedwith a suction conduit '48thatextends through the casing II and commifnicates directly with theinlet 22 in the cylinder head 28. The high temperature evaporator II isconnectedto a suction conduit 48 that communicates with the interior of,the casing. I. The cylinder inlet or port 22 is-in direct communicationwith the interior oi! the casing l8. Accordingly, low pressure vaporfrom the evaporator iilis conducted directly to the cylinder inlet 29and the higher pressure vapor from the 'evaporatoril passes' through theconduit to the interior of the casing l8 and thence through the port 32to the cylinder 22 as the compressor i3 is operated. The compressing ofthe low pressure gas in the cylinder 22 by the higher pressure gasentering through the port 82 'and the-subsequent compression of themixture of gases is accomplished in the same manner as describedheretofore.

4 terior of the casing. .2

3. In refrigerating apparatus, the combination 7 2,128,498 opening 29only. The uncovering of the port 32 In the present embodiment, theinterior of the casing I6 is subjected to the higher pressure vsporentering through the conduit 46 at all times. As both evaporators I 0and II are operated together, flow of vapor through the casing I6 iseffected for cooling at all times that the compressor i3 is actuated.

, From the foregoing, it will be apparent that I I have provided animproved two temperature refrigerating system employing a hermeticallyl0 sealed compressor mechanism having a plurality of vapor inletswherein cooling of the elements and the lubricant withinthe hermeticcasing is effected at all times that the compressor operates. As theinterior of the casing issubjected to cool vapor at relatively lowpressure, less contamination of the lubricant with refrigerant isobtained than with systems wherein the relatively high pressurecompressed vapor prevails in the casing. A concomitant of this operationis the passage of less lubricant to the condenser with the high pressuregas, as is well understood. While I have shown a hermetically sealedcom-\ pressor of the ported cylinder type, it will be understoodthatmyinvention is not so limited and that other types of. multipleinlet compressors spirit of the invention. u While I have shownmyinvention in two forms,

. may be employed without departing fiom the it will beobvious to thoseskilled in the art that 39 I it is not so limited, but is susceptible ofvarious other changes and modifications without depart-' ing from thespirit thereof, and I desire, there- ..fore, that only such limitationsshall be. placed thereupon as are imposed by the prior art or as 36 arespecifically set forth in the appended claims.

What I claim is: -1. In a refrigerating system having first and secondrefrigerant evaporators, the combination of a compressor mechanismincluding a cylinder 40 and a piston movable therein, a casing forhermetically enclosing said compressor mechanism, said cylinderhaving afirst inlet port-for". re-

frigerant vaporized in the first evaporator and a I second inlet portcommunicating withthe space within the hermetic casing for refrigerantvaporize'd in the second evaporator, a conduit for conveying refrigerantvaporized in,the first evaporator to said first inlet port of thecompressor,

said conduit extending through the hermetic casing and a second conduitfor conveying refrigerant vaporized in the second evaporator to theinterior of said hermetic casing.

2. In refrigerating apparatus, the combination of relatively high andlow temperature evapm rators, a compressor mechanism including acylinder and a piston movable therein, a casing for hermeticallyenclosing the compressor mechanism, said cylinder having a first inletport for refrigerant vaporized in the low temperature evaporator and asecond inlet port communicating with the interior'of the casing forrefrigerant vaporized in the higher temperature evaporator,

a conduit extending through the hermetic casing and connecting the lowtemperature evaporator 05 and said first inlet port of the compressor,and a second conduit providing communication between the highertemperature evaporator and the inof relatively high and low temperatureevaporators, a compressor mechanism including a cylinder and a pistonmovable therein, a casing for hermetically enclosing the compressormechanism, said cylinder having a first inlet port for A A arcanerefrigerant vaporized in the higher temperature evaporator andasecondinletport communicating with the interior of the casing forrefrigerant vaporized in the lower temperature evaporator, a conduitextending through the hermetic casing and connecting the highertemperature evaporator and thefirst inlet port of "the compressor and asecond conduit providing communication between the low temperatureevaporator and the interior of the casing. v

4.. In refrigerating apparatus, the combination of relatively high andlow temperature evaporators, a casing, a compressor mechanism disposedwithin the casing and having first and second inlets for refrigerantvaporized in the evaporators, one of said inlets being in communicationwith the interior of the casing, means for conveying refrigerantvaporized in the high temperature evaporator to the second of saidinlets, means for conveying refrigerant vaporized in the lowertemperature evaporator to the interior of the casing, and meanseifective during periods when thejhigher temperature evaporator only isrefrigerated for conveying a portion of the refrigerant vaporizedthereinto the interior of thecasing.

5. In refrigerating apparatus, the combination of relatively high andlow temperature evaporators, a casing, a compressor mechanism disposedwithin the casing and having first and" second inlets for refrigerantvaporized in the evaporators, one of said inlets being in communicationwith the interior of the casing, a first con duit providingcommunication between the low temperature evaporator and the interiorof. the

casing, a second conduit extending through the casing for conveyingrefrigerant vaporized in the higher temperature evaporator to the secondof said compressor inlets, a connecting conduit providing communicationbetween said first and second-mentioned conduits and a plurality ofvalves for controlling the flow of refrigerant through said conduits andeffective during periods when the highertemperature evaporator only isoperated to terminate flow of the lower temperature refrigerant to saidfirst conduit and to pass a portion of the higher temperaturerefrigerant from the second conduit through said connecting conduit tothe interior ofthe casing. v

meme 3. M. BUCHANAN.

